In an optical phase conductor (hereinafter referred to as OPPC), optical units are recombined into the phase conductor, so that optical signals may be transmitted while electric energy is transmitted, and an optical signal transmission link may be established along the road while a power transmission line is erected, to achieve the purpose of using a single material for two functions, thereby saving materials and saving labor.
In 2009, Guangdong Power Grid Corporation developed a novel technology for separating and leading down OPPC optical units. Such novel technology avoids two problems in the original OPPC construction: the first problem is about how to order distribution boards with fixed length according to interface position and distance; and the second problem is about how to install a junction device of high-voltage insulation against ground on a tower to connect the optical unit with a section of fully insulated ordinary fiber optic cable.
The novel construction technology solves the problems of the traditional construction method. The field application result indicates that the novel construction technology not only can avoid distribution boards with fixed cable length and ascending a height for fusion, but also can use conventional lines to connect fittings.
In 2014, Guangdong Power Grid Corporation redeveloped a novel technology for directly leading down plastic-pipe optical units following the photoelectric separation principle in 2009. Through a series of calculations and experiments, on November 14 of the same year, a 110 kV Kaigang line of hangmen Power Supply Bureau is erected, and is put into operation.
The OPPC of a plastic-pipe optical unit makes the problem of high-voltage insulation of a led down section to be easily solved and the manufacturing costs of optical units to be substantially reduced, so that construction becomes more convenient.
However, at present, the achieved technology of separating and leading down OPPC optical units also has certain limitations:
The first limitation is that for a general OPPC optical fiber cable, an optical unit is placed on the internal layer. From the angle of strengthening protection of the optical unit, it is reasonable. However, when the optical unit separation sleeve developed in 2009 is assembled, the optical unit is required to be placed on the secondary external layer.
The second limitation is that when the recombination optical fiber cable comprises two optical units, the two optical units are both required to be separated and led down, causing great difficulty.
The third limitation is that a strain fitting is installed on the cable section of the optical unit separated, thereby being not beneficial to coiling the residual cable for future maintenance.
To accelerate implementation of smart grid, the state already requires that the communication link automatically controlled by the Grid should be synchronously constructed while constructing a 10 Kv distribution line. Therefore, there is a need to continue to overcome the defect existing in the photoelectric separation technology in 2009, in order to quickly promote the goal of photoelectric synchronous construction of the distribution lines.